Vacuum systems operating at varying vacuum rates are commonly employed during arthroscopic and other medical procedures. For example, ablating devices—which vaporize tissue via an electrode—either include or are used with a corresponding aspirating device. A direct correlation exists between the ablation efficiency and the level of vacuum experienced at the distal end of the aspirating device. Too little aspiration can pull in pieces of tissue that are too large for the aspirating device, therefore clogging the device. In contrast, too much aspiration sweeps working bubbles, used to transmit current from the electrode to tissue, off the electrode surface before they can be used to arc through. Such an effect is undesirable, because unnecessary working bubble removal requires an increase in the power output of an electrosurgical unit (ESU) to generate bubbles fast enough to allow the arcing before the working bubbles are aspirated away. Increasing the ESU power output when exposing the devices to a high vacuum is not recommended, as currently known ablators require the lowest possible power setting for use.
Current methods of titrating suction in vacuum systems provide insufficient results. Surgeons customarily use clamps—such as a roller clamp, ratcheted tube clamp or even external clamping devices—to titrate suction in vacuum systems. Clamps allow for full on/full off conditions, but are not effective for any controllable titration at other locations. Holes in the suction tubes are more reliable, but require the user (i.e., the surgeon) to determine where a sliding cover would need to be placed over the system and, thus, require additional input from the user. Accordingly, more transparent, automatic and user-friendly systems are needed.